In situ Observation of Coke Deposition on Zeolite Catalysts Using a Tapered Element Oscillating Microbalance

摘要

A tapered element oscillating microbalance (TEOM) was used to investigate coke deposition on "working" zeolite catalysts with different pore systems, viz. zeolites H-Y, H-ZSM-5, H-ZSM-22 and H-mordenite. The mass changes observed in the acid-catalyzed conversion of 2-propanol to propene and diisopropyl ether as the main products at 100, 150 and 200 deg C were directly correlated to catalyst deactivation as followed by conventional analysis of the product mixture by gas chromatography. While, as expected, the sensitivity of the zeolite catalysts towards deactivation strongly depends on their pore system, the deactivation is not necessarily accompanied by a significant increase in catalyst mass. When catalyst deactivation is absent, i.e., at a low reaction temperature of 100 deg C, the catalyst mass during the conversion of 2-propanol is directly correlated to its adsorption capacity for water at room temperature.